<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>留言板</title>
    <style>
        .container {
            width: 350px;
            height: 300px;
            margin: 0 auto;
            /* border: 1px black solid; */
            text-align: center;
        }

        .grey {
            color: grey;
        }

        .container .row {
            width: 350px;
            height: 40px;

            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .container .row input {
            width: 260px;
            height: 30px;
        }

        #submit {
            width: 350px;
            height: 40px;
            background-color: orange;
            color: white;
            border: none;
            margin: 10px;
            border-radius: 5px;
            font-size: 20px;
        }
    </style>
</head>

<body>
    <div class="container">
        <h1>留言板</h1>
        <p class="grey">输入后点击提交, 会将信息显示下方空白处</p>
        <div class="row">
            <span>谁:</span> <input type="text" name="" id="from">
        </div>
        <div class="row">
            <span>对谁:</span> <input type="text" name="" id="to">
        </div>
        <div class="row">
            <span>说什么:</span> <input type="text" name="" id="say">
        </div>
        <input type="button" value="提交" id="submit" onclick="submit()">
        <!-- <div>A 对 B 说: hello</div> -->
    </div>

    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script>
    <script>
        $.ajax({
            type:"get",
            url:"/message/getList",
            success:function(messages) {
                if(messages==null || messages.length==0){
                    return;
                }
                //2. 遍历数组，构造节点
                for(var message of messages){
                    var divE = "<div>"+message.from +"对" + message.to + "说:" + message.message+"</div>";
                    //3. 把节点添加到页面上
                    $(".container").append(divE);
                }
            }
        });
        function submit(){
            //1. 获取留言的内容
            var from = $('#from').val();
            var to = $('#to').val();
            var say = $('#say').val();
            if (from== '' || to == '' || say == '') {
                return;
            }
            //发送ajax请求，后端进行存储
            $.ajax({
                type:"post",
                url:"/message/publish",
                contentType: "application/json",
                data:JSON.stringify({
                    from: from,
                    to: to,
                    message: say
                }),//JSON.stringify()将对象转成字符串
                success: function (result) {
                    //JSON.parse(result)将字符串转成对象
                    if(result.ok == 1) {
                        //成功
                        //2. 构造节点
                        var divE = "<div>"+from +"对" + to + "说:" + say+"</div>";
                        //3. 把节点添加到页面上
                        $(".container").append(divE);

                        //4. 清空输入框的值
                        $('#from').val("");
                        $('#to').val("");
                        $('#say').val("");
                    }else{
                        alert("添加留言失败");
                    }
                }
            });



            
        }
        
    </script>
</body>

</html>